1. Field of the Invention
The present invention relates generally to wheelchairs, brake units therefor, and brake units for manually-propelled vehicles, and more particularly to a brake unit that is attached to a manual wheelchair or a manually-propelled vehicle so as to increase its safety when a person leaves or sits down on its seat, and a wheelchair including such a brake unit.
2. Description of the Related Art
Normally, a manual brake unit is provided on each of the right and left sides of a manual wheelchair. The manual brake units are provided in front of corresponding right and left rear wheels, and enter in a braking state to brake the rear wheels or in a brake releasing state to release the brakes, depending on the operation position of an operating lever.
For instance, when a user (a care receiver) seated on the seat of the wheelchair rises from the seat, the user is required to stand up after moving the operating lever of the manual brakes provided on the right and left sides so that the brakes enter the braking state to apply braking forces to the rear wheels immediately before leaving the seat.
Some users of such conventional wheelchairs, such as elderly persons with cerebrovascular disease who are extremely forgetful, forget to apply brakes on and stand up from a wheelchair.
Therefore, for instance, when a user such as an elderly person or a disabled person forgets to move the operating lever to the braking position, and touches the frame of a wheelchair to try to sit down thereon again after leaving the wheelchair, the wheelchair may start to move in an unexpected direction since no brakes are applied to the wheelchair. Thus, if a wheelchair moves as a user sits down thereon, the user may lose a body balance so as to totter or tumble.
In order to solve the above-described problem, a wheelchair with a brake mechanism that automatically applies brakes on the wheelchair when a user rises therefrom has been proposed.
For instance, Japanese Patent No. 3103775 discloses a brake unit including a lever provided rotatably under the seat of a wheelchair so as to receive a load imposed when a user is seated on the wheelchair, and a transmission mechanism that is caused to operate by the rotation of the lever so as to pull a brake wire, thereby releasing brakes while the user remains seated on the seat.
In the case of providing a lever mechanism that operates by receiving a load under a seat as described above, for instance, there is a problem in that the lever mechanism under the seat may prevent the wheels on both sides of a manual wheelchair, which are foldable in such directions as to approach each other, from being folded.
Further, a user sits down on the seat to press down the lever by her/his weight. Accordingly, while the user is being seated, the end of the lever remains in contact with the buttocks of the user. As a result, the user may feel discomfort.